Iron Triad-Based Bimetallic M-N-C Nanomaterials as Highly Active Bifunctional Oxygen Electrocatalysts

Mahboob Alam; Kefeng Ping; Mati Danilson; Valdek Mikli; Maike Käärik; Jaan Leis; Jaan Aruväli; Päärn Paiste; Mihkel Rähn; Väino Sammelselg; Kaido Tammeveski; Steffen Haller; Ulrike I Kramm; Pavel Starkov; Nadezda Kongi

doi:10.1021/acsaem.4c00366

Iron Triad-Based Bimetallic M-N-C Nanomaterials as Highly Active Bifunctional Oxygen Electrocatalysts

ACS Appl Energy Mater. 2024 May 2;7(9):4076-4087. doi: 10.1021/acsaem.4c00366. eCollection 2024 May 13.

Authors

Mahboob Alam^{1

2}, Kefeng Ping¹, Mati Danilson³, Valdek Mikli³, Maike Käärik⁴, Jaan Leis⁴, Jaan Aruväli⁵, Päärn Paiste⁵, Mihkel Rähn⁶, Väino Sammelselg⁶, Kaido Tammeveski⁴, Steffen Haller², Ulrike I Kramm², Pavel Starkov¹, Nadezda Kongi⁴

Affiliations

¹ Department of Chemistry and Biotechnology, Tallinn University of Technology, Tallinn 12618, Estonia.
² Department of Chemistry, Catalysts and Electrocatalysts Group, Technical University of Darmstadt, Darmstadt 64287, Germany.
³ Department of Materials and Environmental Technology, Tallinn University of Technology, Tallinn 19086, Estonia.
⁴ Institute of Chemistry, University of Tartu, Tartu 50411, Estonia.
⁵ Institute of Ecology and Earth Sciences, University of Tartu, Tartu 50411, Estonia.
⁶ Institute of Physics, University of Tartu, Tartu 50411, Estonia.

Abstract

The use of precious metal electrocatalysts in clean electrochemical energy conversion and storage applications is widespread, but the sustainability of these materials, in terms of their availability and cost, is constrained. In this research, iron triad-based bimetallic nitrogen-doped carbon (M-N-C) materials were investigated as potential bifunctional electrocatalysts for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). The synthesis of bimetallic FeCo-N-C, CoNi-N-C, and FeNi-N-C catalysts involved a precisely optimized carbonization process of their respective metal-organic precursors. Comprehensive structural analysis was undertaken to elucidate the morphology of the prepared M-N-C materials, while their electrocatalytic performance was assessed through cyclic voltammetry and rotating disk electrode measurements in a 0.1 M KOH solution. All bimetallic catalyst materials demonstrated impressive bifunctional electrocatalytic performance in both the ORR and the OER. However, the FeNi-N-C catalyst proved notably more stable, particularly in the OER conditions. Employed as a bifunctional catalyst for ORR/OER within a customized zinc-air battery, FeNi-N-C exhibited a remarkable discharge-charge voltage gap of only 0.86 V, alongside a peak power density of 60 mW cm^-2. The outstanding stability of FeNi-N-C, operational for about 55 h at 2 mA cm^-2, highlights its robustness for prolonged application.